Process for the preparation of 21-chloro-6,6,9alpha-trifluoro-11beta, alpha, 17alpha-trihydroxy-1,4-pregnadien-3,20-dione 16,17-ketals and selected intermediates

ABSTRACT

6,6-Difluoro-11 Alpha ,16 Alpha ,17 Alpha -trihydroxy-4-pregnen3,20-dione 16,17-ketal 17-ketal is prepared by a process involving the 11 Alpha -microbiological hydroxylation of the corresponding 16 Alpha ,17 Alpha -dihydroxy steroid. The 11 Alpha -hydroxyl is converted sequentially to the 9,11-double bond, 9,11-epoxy and 9 Alpha -fluoro-11 Beta -hydroxyl. Optionally the 1,2-position is dehydrogenated and a 21-hydrogen converted to a 21-hydroxy, acyloxy, bromine or chlorine. The latter steroid ketals are highly active anti-inflammatory and glucocortical agents.

United States Patent n91 Rlpka 1 Feb. 27, 1973 [54] PROCESS FOR THE PREPARATION OF .2l-CHLORO-6,6,9ALPHA-TRIFLUORO- 1 IBETA, ALPHA, 17ALPHA- TRIHYDROXY-l,4-PREGNADIEN-3,20- DIONE 16,17-KETALS AND SELECTED INTERMEDIATES [75] Inventor: William Charles Ripka, Wilmington,

Del.

[73] Assigneez E. l. du Pont de Nemours and Company, Wilmington, Del.

[22] Filed: Feb. 1, 1971 [21] Appl.No.: 111,615

[52] US. Cl.....260 /397.3, 260/239.55 D, 260/397.4, 260/397.45, 424/241, 424/243, 195/51 511 lnt.Cl. .I......'.'c67'"173/00 [58] Field of Search"; "26073971353571, 35745 [56] References Cited UNITED STATES PATENTS 3,338,893 8/1967 Beard et al. ..260l239.55 3,546,215 12/1970 Fried ..260/239.55

Primary Examiner-Elbert L. Roberts Att0rneyAnthony P. Mentis [5 7] ABSTRACT 6,6-Difluoro-1 la,16a,17a-trihydroxy-4-pregnen-3 ,20- dione 16,17-ketal 17-keta1 is prepared by a process involving the Ila-microbiological hydroxylation of the corresponding 16a,17a-dihydroxy steroid. The Hahydroxyl is converted sequentially to the 9,11-doub1e bond, 9,11-epoxy and 9a-fluoro-11Bhydroxyl. Optionally the 1,2-position is dehydrogenated and a 21 hydrogen converted to a ZI-hydroxy, acyloxy, bromine or chlorine. The latter steroid ketals are highly active anti-inflammatory and glucocortical agents.

8 Claims, No Drawings IPROUESS IFOIR TIIII IPIIEIARAIION OF 21- GCIHIILONO-6,6,9AI.IIIA=TRIFILIJORO-l lflE'llA, AILIPIIA, 17JAILPHA-TR1 i YDROXII-l ,4- PRlEGNADIEN=3,20-DIONE 16,17-KETALS AND SELECTED INTERMEDIATES BACKGROUND OF THE INVENTION collagen or skin diseases and the like. Novel precursors l and selected derivatives are described.

2. Prior Art 6,6-Difluoro-4-pregnene-3,20-dione has been prepared by the process of Boswell U.S. Pat. No. 3,219,673. In my commonly assigned copending application Ser. No. 31,001 filed Apr. 22, 1970 it has been demonstrated that 35, 1 6a,1 701,2 l-tetrahydroxy-5- pregnen-ZO-one 16,17-acetonide underwent a series of reactions'with nitrosyl fluoride, alumina, sulfur tetrafluoride, and llfl-hydroxylation (by a microbiological technique) to give an antiinflammatory' agent. Further reactions introduced a 9oz-fluorine and A -unsaturation to provide an even more potent biological agent. In the above sequence of reactions, the yield of the 115- hydrox'ylation is generally quite low and this class of antiinflammatory compounds thus obtained, although very potent, are expensive.

It is known that certain steroids can be microbiologically hydroxylated in the l l-position by selected strains of organisms. The corticoidal activity is in the l lfl-configuration which is obtained by incubating withC'urvularia microorganisms. Although U.S. Pat. No. 3,471,477 indicates this reaction is effective for 6- fluorosteroids, it is known from U.S. Pat. No. 3,530,038 to be dependent upon the substituents on the steroid. Fluocinolone acetonide is prepared commercially by llB-hydroxylation on a 6a-fluoro precursor. However, attempts to carry out the same reaction on 6m,6,B-dilluoro steroids give extremely low yields. liiydroirylation by selected organisms is also known to give ll a-hydroxyl. This has been applied to a 6amonohalo pregnene as shown in U.S. Pat. No. 3,033,759. Even if applicable to 6,6-difluoro steroids, several further transformations would be needed to convert this to the 113 compound, which is the isomer needed for antiinflammatory use.

SUMMARY OF THE INVENTION According to this invention new compounds of the formula I t I 6H3 wherein X is 2 ""Wfi kfibr 0=. it is and R is acyi of up to four carbon atoms, particularly acetyl, are converted by a sequence of reactions to further novelcornpounds of the formula II CHs ogq m v wherein R and R are each OH, or together are a double bond between the 0-1 6 and C-1 7 carbon positions, proviso that R is H when and IR is H or OH, with the R and R are a double bond.

These compounds in turn are converted by a sequence of reactions to further novel compounds of the formula:

(Ill) by selected organisms to provide a high yield of the lla-hydroxyl. The latter is converted by a series of reactions, as herein-after ,shown to give the HB- hydroxyl, necessary for high corticordal activity.

DETAILED DESCRIPTION OF THE INVENTION It has now been discovered that 6,6-difluoro-3,20- diketo-l60:,17a-dihydroxy-4-pregnene can be microbiologically hydroxylated to the lla-hydroxyl in good yields. The complete process starting with a readi-' ly available pregnene is illustrated by the following reaction scheme:

(1) CHaSOzCl (2) Cl The starting steroid used in this reaction scheme is readily available. In the above procedures the R group represents a lower alkanoyl radical, e.g., acetyl, propionyl or butyryl, in the 3- or 2l-positions where applicable. Generally, however, the acetyl is preferred since it is readily available and reactive.

R and R of the ketal grouping usually are methyl as in the acetonide but can also be individually such other groups as, for example, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, cyclopentyl or cyclohexyl and can together form the tetramethylene or pentamethylene radical. The desired ketal is prepared from the appropriate ketone and the 16a, 17adihydroxy steroid in the presence of an acid catalyst.

The first stepla) of the instant process, the reaction of a 3-alkanoyl- A -pregnadiene with nitrosyl fluoride at the 5,6-positions is carried out in an inert solvent; for instance, a halogenated hydrocarbon, such as methylene chloride, chloroform, carbon tetrachloride, fluorodichlormethane, and ethylene chloride, or mixtures of these with glyme, acetonitrile, and sulfolane. Nitrosyl tetrafluoroborate can be added with nitrosyl fluoride in this step. A mixture of these two materials is much more efficient than nitrosyl fluoride alone. Higher yields of 5fluoro6-nitriminopregnene are obtained in this manner. Nitrosyl tetrafluoroborate, which is a crystalline solid, can also be made in situ by using a mixture of nitrosyl fluoride and of boron trifluoride. The molar ratio of nitrosyl fluoride to nitrosyl tetrafluoroborate in the mixture can be varied within rather broad limits, e.g., 50:1 to 1:50. Usually the optimum ratio is 1:1.

The amount of nitrosyl fluoride employed must, of course, be at least stoichiometric, i.e., two moles per mole of the starting A -pregnene. However, it is advantageous to use an excess of nitrosyl fluoride. An initial molar ratio of nitrosyl fluoride to the A -pregnene of about 3 to 1 has been found to be particularly practical, high yields of the 5-fluoro-6-nitrimino-16-pregnene being obtained in short times.

The reaction is carried out at moderate temperatures, preferably no higher than about C and especially within the range of about l0 to 30C. Within this range, the reaction rates are satisfactory and can be easily controlled. Atmospheric pressure is sufticient, although higher pressures may sometimes be required to maintain a sufficient concentration of the reactants at the reaction temperatures. Moisture is undesirable in this step because of the danger of NOF and/or NOBF hydrolysis.

The nitrosyl fluoride adduct obtained in the first step, the S-fluoro-G-nitrimino-lo-pregnene, can be isolated in any conventional manner, such as for example evaporation of the solvent and recrystallization of the residue. in practice, this isolation and purification step is not required, and the crude solution can be directly subjected to the next step (b), i.e. conversion of the nitrimino group to the keto group.

The solution may be contacted with a weak base, such as an aqueous alkali bicarbonate, to remove excess NOF and/or NOBF, and acidic reaction side products. The solution is chromatographed on neutral alumina containing 5-15 percent by weight of water (activity grade III). The 5-fluoro-6-keto-l6-pregnene formed in this step is eluted with a suitable solvent or a solvent combination, such as aliphatic or aromatic hydrocarbons. Instead of the chromatographic technique, any other suitable technique for contacting the fluoronitrimino-l6-pregnene with wet alumina can be used; for example, vigorously stirring a suspension of alumina in the fluoronitriminopregnene solution of the steroid in aqueous dioxane.

The reaction of the 5-fluoro-6-keto-16-pregnene obtained from step (b) with sulfur tetrafluoride/hydrogen fluoride or sulfur tetrafluoride/Lewis acid mixture is carried out in step (c) in an inert solvent of the same type as those used in the first step, i.e., methylene chloride, chloroform, carbon tetrachloride, fluorodichloromethane, ethylene chloride, and the like. Sulfur tetrafluoride can be replaced by selenium tetrafluoride or by an organosulfur fluoride, such as phenylsulfur trifluoride, but sulfur tetrafluoride is the cheapest and the most readily available reagent. Since both sulfur tetrafluoride and hydrogen fluoride are gases at the reaction temperature, it is practical to carry out this step in a closed reactor, such as a shaking autoclave. The reaction is best carried out at moderate temperatures, below about 100C, and preferably at 10 to 30C. It usually is not practical to lower the temperature below about 10C because the reaction rates are too low for an eflicient operation.

The relative proportions of sulfur tetrafluoride and of hydrogen fluoride can be varied within a rather broad range; the molar proportion of hydrogen fluoride in admixture with sulfur tetrafluoride can be as low as zero or as high as about 90 percent, the 15-20 percent range being preferred. Although other fluoro Lewis acids, such as BF and SbF,, can be used, hydrogen fluoride, either added directly or generated in situ is preferred. Hydrogen fluoride can be generated in situ by adding to the reaction mixture a compound containing at least one active hydrogen, such as water or alcohol. Reaction of such an active hydrogen-containing compound with sulfur tetrafluoride liberates hydrogen fluoride. The 5,6,6-trifluoro-l6-pregnene can be recovered by conventional methods, such as evaporation of solvent and recrystallization of the residue or column chromatography.

Hydrolysis of the C-3 ester group (step d) is readily accomplished by contacting a solution of the steroid in a water-miscible solvent with aqueous alkali, such as sodium or potassium carbonate, or sodium hydroxide. This step is usually carried out at room temperature, but the temperature range of about l to 35C can conveniently be employed. Suitable solvents include lower alcohols, such as methyl, ethyl, propyl, isopropyl and t-butyl; and water-miscible ethers, such as tetrahydrofuran and dioxane. Methyl alcohol/tetrahydrofuran mixtures are preferred because of their good solvent properties towards both the steroid compound and the aqueous alkali.

The 3-hydroxyl is then oxidized to the 3-keto group (step e) in any conventional manner known to the art, e.g., with chromic acid. The preferred reagent is a solution of chromic acid and sulfuric acid in water [L. F. Fieser and M. Fieser, Reagents for Organic Synthesis, John Wiley & Sons, p. 142 (1967)]. The 3-hydroxysteroid is dissolved in a water-miscible solvent, such as an ether or a ketone, e.g., dioxane, tetrahydrofuran, acetone, or methyl ethyl ketone. The reaction is carried out at or below room temperature, although a temperature of up to about 35C can be used.

Dehydrofluorination of the 5-keto-5,6,6-trifluoro-l6 -pregnene to the A,l6-3-keto-6,6-difluoropregnadiene is done in the presence of a base, such as alumina, potassium carbonate, silver oxide, potassium hydroxide, or lithium carbonate (step f). Although a nonaqueous medium, such as methanol or ethanol is desirable, the reaction sometimes can be carried out in the presence of water. The dehydrofluorination occasionally requires heating, even to reflux, but usually is accomplished at about room temperature.

Oxidation of the C-l6, C-l7 double bond without effect on that between C-4 and C-5 (step 3) is carried out with oxidizing agents such as potassium permanganate in acetone/acetic acid at OIOC. Other agents for this transfonnation such as osmium tetroxide are also effective.

Microbiological hydroxylation that takes place in the Ila-position is carried out by the general technique employed for hydroxylation except that the microorganism must be specific to one that introduces the desired configuration. The organism is generally grown on an agar slant medium useful to propogate the organism and the latter then introduced into liquid culture flasks and then agitated for several days with the steroid, following which the lla-hydroxy steroid is extracted. Useful organisms for the lla-hydrox-ylation are of Aspergillus family as described in US. Pat. No. 3,033,759. A further useful organism is Rhizopus nigrican. The surprising feature is that the yields are quite high for the l lei-hydroxylation of 6,6-difluorosteroids whereas 1 lB-hydroxylation is very low.

Conversion of the l6a,l7a-hydroxyls to acetals, e.g., acetonide, with the ketones mentioned above takes place with an acid catalyst (step i). This leaves the 1 lahydroxyl as the only hydroxyl which can be esterified and removed (use of a sulfonyl halide such as ptoluene-sulfonyl chloride, or methanesulfonyl chloride generally at 0-25C, followed by treatment with an alkali metal alkanoate at 50-100C,j and k) to give the 9-ll unsaturation.

Addition of the preceding steroid with hypohalous acid (which can be generated in situ and reacted at 2035 C gives the l lB-hydroxy-9a-halo steroid. Preferred is the hypobromous acid as shown in (1). Treatment of the latter with abase, preferably an alkali metal alkanoate at 50-l00C results in the 9,1l-positions giving the corresponding epoxy (also called oxide or oxy) as shown in equation m.

The latter epoxy steroid reacts with HF suitably added as a complex of HF with a base such as urea to about room temperature (11). The steroid thus formed has the desired configuration for enhanced corticosteroid activity, namely a lIB-hydroxyl and 9a-fluorine.

Further transformations to even more active anti-inflammatory steroid can be effected by conversion of a 2l-hydrogen to hydroxy or halogen, especially chlorine and also dehydrogenation at the 1,2-position to give the A--steroid. One scheme is shown in equations o,p,q,r, and s. The A -unsaturation can optionally be introduced by a microbiological dehydrogenation with Arthrobacter simplex or by chemical means such as dichlorodicyanoquinone or equivalent dehydrogenation agents. The A -unsaturation can be introduced at any stage by the latter methods after step n, i.e., after the B-hydroxyl has been formed.

Selected pregnenes with an llfl-hydroxyl are useful in the treatment of allergic, collagen, skin and musculosketal diseases. They can be administered orally, parenterally or topically with dosage rates in the range of 0.0001 to 1 mg. per kg. of body weight per day.

New intermediates to the highly active corticosteroids (as obtained by use of all or the main sequential reactions) are represented by the formulas previously shown. Intermediates can also be used as progestational agents or as antiandrogens.

SPECIFIC EMBODIMENTS OF THE INVENTION The following examples are illustrative, not limita- 'Acetate (3) tive, ofthe practice of the invention. All parts are by EXAMPLE 1 I 5 a-Fluoro-Bfl-hydroxy-l 6-pregnen-6,20-dione Acetate(2) 1. NOF or NOBF4/NOF 2. micron sill SB-Hydroxy-S,16-pregnadien-20-one acetate (1) (75 g, 0.211 mole) in 600 ml of methylene chloride, cooled to 0", was treatedv with .25 g (0.51 mole) of nitrosyl fluoride. The reaction was stirred at 0 forv 3 hrs. then 'carefullywashed with aqueous sodium bicarbonate,

water and brine. The organic layers were dried with anhydrous magnesium sulfate and the solvent evaporated to give a viscous green oil. This oil in benzene was apmethylene chloride was added to a mixture of 40 g (0.342 mole) of nitrosyl tetrafluoroborate in 500 ml of glyme cooled to 0. At the same time nitrosyl fluoride (40 g, 0.815 mole) was bubbled in over l -hr. The reac-- tion was stirred for 4 hrs. at 0 then poured into cold brine. The organic layer wasseparated, washed twice more with brine, then evaporated by a stream of nitrogen to give a viscous green oil (volume of ca 300 ml). This was slurried with 3 kg of alumina 111 in 1 l. of hexane. After stirring for 4 hrs the product was eluted from the alumina'with benzene (8 l.) to give 99 g of crude material. Recrystallization from methanol gave 82.3 g. Chromatography of the motor liquors on Florisil gave an additional 8.0 g for a total of 90.3 g (66 percent) of steroid (2). An analytical sample was crystallized from acetone-hexane, m.p. 196-1975. Anal. Calcd. for C,,H ,O,F: C, 70.74; H, 7.99; F, 4.86

Found: C, 70.41, 70.70; H, 7.58, 8.05; F, 4.81, 4.85.

' Ultraviolet (ethanol): 303 mp. (K 0.29, @190 237 my. (K 22.8, 58,580) infrared (KBr): 3.25 p. (==CH); 5.79 p. (acetate and 6 0); P 2o 631 I uF rl) B. a,6,6-Trifluoro-3B-hydroxy-16-pregnen-20-one $66135 g, amino flesh abate iinso'ni I of methylene chloride and 6.3 ml of water (.35 mole) 5 was reacted with 115 g (1.065 mole) of sulfur tetrafluoride at 10- for 18 hrs in a sealed l-lastelloy bomb. The reaction was then poured into water and the separated organic layer washed with aqueous sodium bicarbonate, water and brine. It was dried (magnesium sulfate) and the solvent evaporated. The residue was chromatographed on 400 g of Florisil and eluted with 3 to 5 percent acetone-hexane to yield, after recrystallization from acetone-hexane, 24.0 g (91 percent). An analytical same was recrystallized twice from acetonehexane, m.p. 177-178C for 5a, 6, 6-trifluoro-3fihydroxy-l6-pregnen-20-one acetate (3) Anal. Calcd. for C H,,O,F C, 66.96; H, 7.58; F, 13.82.

Found: C, 66.76; 11,765; F, 13.77 Ultraviolet (ethanol): 322 my. (K 0.129,:53)

237 my. (K 23.6, e 9,720)

Infrared (KBr): 5.77 p. (acetate C=O); 6.0 (C, ==O);

Potassium hydro itide 8.2 g, 0.147 mole) n20 ml of I water was added to. 800 ml of tetrahydrofuran and 250 ml of methanol. The solution was cooled to 0C and I ane) to give, after recrystallization from acetone-hexane, an analytical sample, m.p. 182-183C for 5a,6,6- trifluoro-3B-hydroxy-l6-pregnen-20-one (4). Anal. Calcd. for C l-15 F 05 C, 68.07; H, 7.89; F, 15.38;

FoundzC, 68.32,68.46;l-l,7.74,7.82;F, 15.45, 15.40;

Ultraviolet (ethanol): 322 rnp, (K 0. 147,e54); 237 mp.

P w n)- D. 6,6-Difluoro-4,l6-pregnadien-3,20-dione (6) Ultraviolet (thaiidl): 303 mp. K 0.187, 671

Infrared (KBr): 2.94 p. (0H); 3.25 p. (=CH); 5.88 p. (C, =O) 5.98 1. (C O).

5 F. 6,6-Difluoro-l 101,1 6a,]7a-trihydroxy-4-pregnen- &/

J on on Steroid 4 (18.7 g, .0505 mole) in 300 ml of acetone at 0C was treated with Jones reagent until a persistent red color was obtained. The reaction was also followed 0 Q/ to completion by observing the disappearance of start- 15 ing material by thin-layer chromatography (5 percent ethyl acetate-chloroform; silica gel plates). Methanol was added to quench excess reagent. The mixture was Six 250 ml flasks, each containing 0.5 g soybean then filtered and the filtrate concentrated, then diluted meal, 2.0 g dextrose, 0.5 g yeast extract, 0.5 g sodium with water. Extraction with methylene chloride gave a chloride, 0.5 g potassium phosphate (dibasic) and semi-solid residue (5a,6,6-trifluoro-l6-pregnen-3,20- distilled water (100 ml) with the pH of the mixture addione, product of equation (e) in the previously menjusted to 6.5 with concentrated hydrochloric acid, was tioned reaction scheme) which was chromatographed innoculated with Aspergillus ochraceus ATCC 18500. directly on alumina III (500 g) and eluted with benzene These flasks were placed on a rotary shaker and to yield 14.0 g (79.5 percent). An analytical sample of vigorously agitated for 48 hrs. at 29C. After this time the 6,6-difluoro-4,l6-pregnadien-3,20-dione (6)was they were transferred to six 21. flasks (each containing crystallized twice from acetone-hexane, mp 400 ml of the broth described above) and further 118.5-1 19.0Ex grown at 29C with agitation, for 24 hrs. Steroid 7 (1.0 Anal..Calcd. for C, H O,F,: C, 72.39; H, 7.52; F, g,2.62 mole) in6ml of dimethyl formamide was evenly 10.91. 30 distributed among the six flasks and shaking continued Found: C, 72.46; H, 7.64; F, 11.13. for 96 hrs. The contents of the flasks were then com- Ultraviolet (ethanol): 325 mp. (K 0.23, e 80) binedand filtered first through a coarse sintered glass 234 u Infrared filter then through Celite. The filtrate was then ex- (=CH): 5.90 p. (C O); 6.02 p (C, =O); 6.29 p. 35 tracted with ethyl acetate (total of ca6 1.). The organic iF extract was washed with water, brine dried (magnesium m y y- -p g ,2 sulfate) and evaporated under nitrogen. The resulting dione residue was triturated with ethyl acetate to give 630 mg of a brown powder. The mother liquors from this trituration were chromatographed on silica gel (eluted with ethyl acetate) to yield an additional 133 mg of material. An anal-ytical sample of the 6,6-difluoro-l 1a,l6a,l7atrihydroxy-4-pregnen-3,20-dione (8)was crystallized twice from acetone-hexane, m.p. 203208C.

Infrared (KBr): 2.89 and 3.02 p. (OH); 3.25 p. (=CH); 5 .87 [.L shoulder, 5.92 p. and 6.0 p. shoulder related to s 7 G. 6,6-Difluoro-l1a,16a,17a-trihydroxy-4-pregnen- Steroid 6 (9.10 g, .026 mole) in 253 ml of acetone 3zo'dione l6l7'acetonide (9) and-3.1 ml of glacial acetic acid was cooled to 3 C in an ice-bath. A solution of 4.10 g of potassium perman- ----0H ganate in 195 ml of 85 percent aqueous acetone HO-- -OH (cooled to 3C) was added in one portion. After 4 min.

the reaction was treated with 42 ml of saturated aqueous sodium sulfite. It was then filtered through Celite and the filtrate extracted with methylene chloride. The organic extract was washed with water, brine, and dried with magnesium sulfate. The solvent was evaporated and the residue triturated with acetone to give 6 g of 8 3 Cm material. Recrystallization from acetone-hexane gave 4.0 g 40.5 percent) of 6,6-difluoro-16a,17a-dihydrox- [Jw MH. y-4-pregnen-3,20-dione (7) m.p. 202-207C. An

analytical sample was recrystallized three times from acetone-hexane, m.p. 213-217C (sealed tube). Anal. Calcd. for C,,H,,,O F,: C, 66.95; H, 7.38; F, 9.94 0- Found C, 66.17, 66.59, 65.97; H, 7.43, 7.47, 7.45; F, 9.53. n

Steroid 8 (630 mg, 1.58 mmole) in 50 ml of acetone was treated with 1 drop of 37 percent hydrochloric acid. The progress of the reaction was followed by thinlayer chromatoatography (t.l.c.) (75 percent ethyl acetatezbenzene; silica gel plates) and appeared complete for 20 hrs. The reaction was concentrated under vacuum to about 5 ml. The resulting precipitate was filtered to give 463 mg (one component by t.l.c. using silica gel plates with 75 percent ethyl acetate1benzene). Preparative t.l.c. yielded an additional 50 mg of product to give 513 mg (74 percent) overall of 6,6-difluoro-l1a,16a,17a-tri-hydroxy-4- pregnen-3,20-dione 16,17-acetonide (9). An analytical sample was recrystallized twice from acetone-hexane, m.p. 300-302C.

Anal. Calcd. for C H F O C, 65.74; H, 7.36; F, 8.67.

Found: C, 65.93; II, 7.48; F, 10.26.

Ultraviolet (ethanol): 300 my. (K 0.28, 123

Infrared (KBr): 2.88 p. (OI-I); 5.85 p. (C, ==O); 5.90 p, F

I-I'. 6,6-Difluoro-l 1d,16a,1 7a-trihydroxy-4-pregnen- 3,20-dione 16,17-acetonide l l-mesylate (10) C1121 uoo CH3 F2 -----0 CH: MsO-- A solution of steroid 9 (330 mg, 0.75 mmole) in 2.5 ml of pyridine was treated with 0.57 ml of methanesulfonyl chloride and allowed to stand at C for 24 hrs. The dark solution was diluted with 20 m1 of methylene chloride, washed with 20 ml of 5 percent aqueous hydrochloric acid and with 20 ml of water. It was dried over magnesium sulfate and the solvent evaporated to give 490 mg of a yellow oil of the corresponding mesylate (10).

Infrared (neat): 5.85, 5.90 p. (C =O and C,=O); 6.10 and 6.15 p, (ArC=C); 7.3 and 8.5 p. (SO,-O)

I. 6,6-Difluoro-l6a,l7a-dihydroxy-4,9(l l pregnadiene-3,20-dione 16,17 -acetonide (1 l The mesylate steroid 10 (490 mg) as obtained above and 490 mg of anhydrous sodium acetate were mixed with 6 ml of glacial acetic acid and the mixture was refluxed for 2 hrs. It was then diluted with water and the resulting precipitate was filtered and air-dried to Steroid 11 (170 mg, 0.405 mmole) in 5 ml of dioxane was treated with 0.26 ml of 0.5N perchloric acid and 81 mg of recrystallized N-bromoacetamide. The reaction was stirred at 25C, in the dark, for 4 hrs. An aqueous solution of mg of sodium bisulfite in 3 ml of water was added dropwise to discharge the yellow color. The reaction was then diluted with ice water (20 ml) and extracted with methylene chloride. The organic extracts were washed three times with an equal volume of water,then brine and finally dried (magnesium sulfate) and the solvent evaporated to give 251 mg of a yellow oil of 6,6-difluoro-9a-bromo-l15,1601, 17a-trihydroxy- 4-pregnen-3,20-dione 16,17-acetonide (l2) Infrared (neat): 290 p. (OH); 5.88 p, (C, =0); 5.95 (C =0). K. 6,6-Difluoro-16a,l7a-dihydroxy-9B,1 1B-epoxy-4- pregnen-3,20-dione 16,17-acetonide (13) The steroidal bromohydrin 12(251 mg) as obtained above was taken up in 10 mlv of acetone, treated with 310 mg of anhydrous potassium acetate and refluxed for 2 hours. The acetone was evaporated under vacuum andthe residue diluted with icewater. The resulting precipitate was filtered and dried to yield 159 mg. Recrystallization from acetone-hexane gave mg. m.p. 201 .5-203.0C of 6,6-difluoro-l 6a, 1 7a-dihydrox- NMR (CDCl,): 46 cps (Pl-l8); 70 and 88 cps (acetopregnen-3,20-dione 16,17-acetonide (14) l l6 y-9fl,l lB,epoxy-4-pregnen-3,20-dione 16,17-aceto- Br nide (13 lR Infrared (KBI'): 5.84 [L (C=0); 5.92 p. (C5=-O).

Ultraviolet (EtOl-l): 300 mp. (K 0.28,: 123) 227 mp, (K 25.8,e 11,400)

nide curs 92 cps (ll-l9; 214 cps (H-ll); 301 and 306 cps (11-16); 279 and 283 cps (Pl-4). L. 6,6,9a-Trifuloro-l 13,1601, 1 7a-trihydroxy-4- 6,6,9a-Trifluoro-l 1 13,1611, 1 7a-trihydroxy-4- pregnen-3,20-dione 16,17-acetonide (100 mg) in 10 ml of tetrahydrofuran at 50C was treated with 165 mg pyridinium bromide perbromide. The mixture was stirred at 50 to 60C for 1 hr. after which time an additional 90 mg of pyridinium bromide perbromide was added. Stirring was continued at 50 to 60C for 4 hrs.

Steroid epoxlde 13 above 8 0-257 mmole) The reaction was poured into ice-water and the was mixed with urea'hydomgen fluoride precipitate filtered. The solid was crystallized from Pl and the leactlonmred 25 for 5 The acetone-hexane after treatment with charcoal to yield tion was then poured Into a mixture of 10 ml of concen- 66 mg of 2 21 dib 6 6 9 t if] l 1 1 17, rated ammomum hydroxlde and 50 8 of The trihydroxy-4-pregnan-3,20-dione 16,17-acetonide resulting precipitate was filtered, washed well with 5 This material (66 mg) with 100 mg anhydrous water and dried to yield 60 material was lithium chloride and 4 ml of dimethyl formamide was chromatographed s of Florlsll and eluted with refluxed for 8 hrs. at which point an additional 100 mg acetone'hexane fractmns to gwe 45 of of lithium chloride was added. Refluxing was continued Trifluom'l mwal7a'trlhydmxy'4'pregnen'3,20" for 4 hrs. then the reaction was cooled, poured into ice :23 ggrs gl g z u z gg from water and the precipitate filtered and dried to give 50 a mg of 21-bromo-6,6,9a-trifluoro-l15,16,170:- glig'g fiffi fg 14; trihydroxy-l ,4-pregnadien-3,20-dione 16,17-acetonide M 1 16 17 21 h (16). This crude material (50 mg), 25 mg of potassium :tetra ydmxy acetate and 5 ml of dimethylformamide were heated at l,4-pregnad1en-3,20-dlone 16,17-acetomde ZI-acetate when complete as determined by thimlayer chro matography, the reaction was poured into water and a extracted with methylene chloride. The organic extracts were washed with water, brine, dried (MgSO HO and concentrated. The residue was chromatographed on 3 g of Florisil and eluted with acetone-hexane mixtures to give 6,6,9a-trifluoro-l1fi,16a,l7a,2li tetrahydroxyl ,4-pregnadien-3 ,20-dione 16,17-aceto- 1'? nide 2l-acetate, mp. 284286C (17). V N. 2l-Chloro-6,6,9a-trifluoro-llB,l6a,l7a-trihydrox- Fz y-l,4-pregnadien-3,20-dione 16,17 acetonide (19) ll CHzOC-CH:

A sample of Zl-acetate (17) was hydrolyzed with potassium carbonate and water in tetrahydrofuranmethanol solution. The crude 6,6,9a-trif1uoro-11 [3,1 601,1 7a-tetrahydroxy-l ,4-pregnadien-3, 20-dione 16,17-acetonide (100mg) (18) in 3 ml of pyridine at was treated with 34 p1 of methane-sulfonyl chloride. The solution was allowed to warm to 25 and was stirred for 24 hrs. In was then poured into water and the resulting precipitate filtered. This solid was taken up up in 15 ml of methylene chloride, dried (anhydrous magnesium sulfate), and the solutionwas then added slowly to a refluxing mixture of 70 mg of lithium chloride in 6 ml of dimethylformamide. The reaction was refluxed for 1 hr. after the addition was complete and then allowed to stand at 25 for 25 hrs. It was poured into icewater and the precipitate filtered. Crystallization from acetone-hexane gave 60 mg, mp. 2852 87 C of 21' chloro-6,6,9a-trifluoro-l 113,16a,l7a-trihydroxy-l,4- pregnadien-3,20-dione 16,17-acetonide (l9). Ultraviolet: Hi9," 234mp. (e, 16,100) 297mg. (K 0.49) Mass SpectrumzCalcd. for C H O F CI: 488.1576

Measured: 488.1582

The processes described give biologically active steroids. Compounds 5-1 1 exhibit pregestational and antiandrogenic properties and compounds 12-15 show anti-inflammatory effects. These compounds are also intermediates in the preparation of compounds 16-19 which are highly active glucocorticoidal and antiinflammatory agents. The excellent topical and oral antiinflammatory activity isshown by the following procedure:

Topical Antiinflammatory Assay (rat ear assay) Intact male 21-day-old rats (60-70 g.) were anesthetized and the test compound in a vehicle of 20 percent pyridine,5% distilled water, 74 percent diethyl ether, and 1 percent croton oil by volume was applied to the left ear, 0.05 ml. to the inside of the ear and 0.05 ml. to the outside. One group of 9 rats received vehicle only, 3 groups (six to seven rats per group) received 3X dose increments of compound in vehicle, and 3 groups (six to seven rate per group) received 3X dose increments of fluocinolone acetonide, the test standard, in vehicle. Six hours later, the rats were sacrificed and ear pieces of uniform size were punched out with a No. 4 cork borer. The ear pieces were weighed, and the mean weights for the controland test substance-treated groups were calculated. Plots of percent decrease from control versus log dose were made, and the doses of the compound and of test standard (in mg. per kg. of body weight) which caused a 30 percent reduction from control ear pieces weight were determined from doseresponse lines fitted visually. ED30% values were com-' 7 pared to give potency ratios of compounds with respect wherein X is H0 R10 or 0: and

R is acyl of up to 4 carbon atoms. 2. A steroid compound according to claim 1 wherein X is 5 a,6,6-trif1uoro-3fi-hydroxy-16-pregnen-20-one acetate.

3. A steroid compound according to claim 1 wherein X is 5 a,6,6-trifluoro-3B-hydroxyl 6-pregnen-20-one.

4. A steroid compound according to claim 1 wherein X is O; 5a,6,6-trifluoro-16-pregnen-3,20-di0ne.

5. A steroid compound having the formula wherein R and R are each OH, or together are a double bond between the C-16 and C17 carbon positions and 19 20 R" is H or H, witlTthe proviso that R is H when R R and R are each OH andi is fi; 6,6-difluoro-l6a,l7

and R are a double bond. a-dihydroxy-4-pregnen- 3,ZQ-dione.

6. A steroid compound according to claim 5 wherein 8 A Steroid com pound according to claim 5 wherein R2 Rs are a 'j F the R, R and R are each on; 6,6-difluoro-lla,l6a,l7a- C-l6 and C-1 7 carbon positions and R is H; 6,6- 5 trihydroxy 4 re "ems 20 dione difluoro-4,l6-pregnadiene-3,20-dione. p g

7. A steroid compound according to claim 5 wherein a a:

Disclaimer 3,718,673.-William Uharles Riplca, WVilmington, Del. PROCESS FOR THE PREPARATION OF 21-CHLORO-6,6,9ALPHA-TRIFLUORO- llBETA, ALPHA, l7ALPHA-TRIHYDROXY 1,4 PREGNA- DIEN-8,20-DIONE 16,17-KETALS AND SELECTED INTER- MEDIATES. Patent dated Feb. 27, 1973. Disclaimer filed Mar. 1, 1974, by the assignee, E. I. du Pont de N emom's and Company. Hereby enters this disclaimer to claims 5 and 7 of said patent,

[Ofiicz'al Gazette August 27, 1974.] 

2. A steroid compound according to claim 1 wherein X is 5 Alpha ,6,6-trifluoro-3 Beta -hydroxy-16-pregnen-20-one acetate.
 3. A steroid compound according to claim 1 wherein X is 5 Alpha ,6,6-trifluoro-3 Beta -hydroxy-16-pregnen-20-one.
 4. A steroid compound according to claim 1 wherein X is O; 5 Alpha ,6,6-trifluoro-16-pregnen-3,20-dione.
 5. A steroid compound having the formula
 6. A steroid compound according to claim 5 wherein R2 and R3 together are a double bond between the C-16 and C-17 carbon positions and R4 is H; 6,6-difluoro-4,16-pregnadiene-3,20-dione.
 7. A steroid compound according to claim 5 wherein R2 and R3 are each OH and R4 is H; 6,6-difluoro-16 Alpha ,17 Alpha -dihydroxy-4-pregnen-3,20-dione.
 8. A steroid compound according to claim 5 wherein R2, R3 and R4 are each OH; 6,6-difluoro-11 Alpha ,16 Alpha ,17 Alpha -trihydroxy-4-pregnen-3,20-dione. 